Inline veneer production system

ABSTRACT

A system for efficiently utilizing a wood veneer peeling lathe and dryer by installing a number of horizontally disposed and vertically spaced veneer storage and conveying trays spanning from the peeling lathe to the dryer. More levels of trays are provided than levels of conveyors in the dryer to insure a ready source of veneer to keep the dryer supplied with no gaps between pieces of veneer. A waste removal clipper may be positioned between the ends of the trays for removal of defective portions of veneer. The wetter portions of veneer can be conveyed to a slower dryer conveyor while the drier portions can be conveyed on a faster dryer conveyor without overdrying.

United States Patent [72 I lnventor Harold E. Erickson Federal Way.Wash. (21] Appl. No. 540.796 [22] Filed Apr. 6, 1966 Division of Ser.No. 315.248. Oct. 10. 1963. Pat. No. 3,280,866 [451 Patented Mar. 2,1971 [73] Assignee Weyerhaeuser Company Tacoma, Wash.

[54] lN-LINE VENEER PRODUCTION SYSTEM 9 Claims, 4 Drawing Figs. [52}U.S. Cl. 144/327, 144/3 [51] Int. Cl B27l 5/02 [50] Field ofSearch144/327, 324, 314, 317, 309, 209, 3,1 5 6] References Cited UNITEDSTATES PATENTS 2,844,174 7/1958 Ware et al. 144/281 PrimaryExaminer-Donald R. Schran Attorneys-Leslie G. Noller, John M. Crawford,Daniel C.

Block and Patrick D. Coogan ABSTRACT: A system for efficiently utilizinga wood veneer peeling lathe and dryer by installing a number ofhorizontally disposed and vertically spaced veneer storage and conveyingtrays spanning from the peeling lathe to the dryer. More levels of traysare provided than levels of conveyors in the dryer to insure a readysource of veneer to keep the dryer supplied with no gaps between piecesof veneer. A waste removal clipper may be positioned between the ends ofthe trays for removal of defective portions of veneer. The wetterportions of veneer can be conveyed to a slower dryer conveyor while thedrier portions can be conveyed on a faster dryer conveyor withoutoverdrying.

lN-olllih VENEER PRODUCTHON SYSTEM This is a division of applicationSer. No. 315,248, filed Oct. 10, 1963, now U.S. Pat. No. 3,280,866issued Oct. 25, 1966. This invention relates to the production of woodveneers and in particular to an improved process and apparatus forinline production of wood veneers.

in conventional prior art systems of softwood plywood production,veneers are clipped wider than the finished sheet in order to accountfor an indefinite amount of shrinkage and sorted before they are dried.Sorting is done visually and is determined by the amount and size ofknotholes, splits and rough surface and also by rough estimates ofmoisture content. Such moisture content is difficult to estimate whilethe veneer is still wet and before it passes through a dryer. Effectiveinstruments for this purpose are not presently available. Thus, severalveneer sheetsare clipped improperly since they contain both relativelywet and relatively dry portions in one sheet. When such a sheet passesthrough the dryer at a sufficient speed to dry out the wet portion ofthe sheet, the dry portion becomes overdry and the resulting damagedegrades the veneer and results in a lower commercial grade veneer.

The sheets of veneer are passedthrough the dryer in the prior artsystems with the long axis of the veneer grain iengthwise to its paththrough the dryer. This is termed lengthwise drying and includes thedrying of wood veneers in which the veneer passes through the dryer withits grain lengthwise to its direction of travel. This is in distinctionfrom crosswise drying which includes the drying of wood veneers in whichthe veneer passes through the dryer with its grain crosswise to itsdirection of travel.

In the production of hardwood veneers, logs are often peeled and reeled.These reels are then transferred to the dryer and unrolled through thedryer to be clipped after they have been dried. This is done to allowthe clipper operators to select matching pieces of the veneer and morecarefully clip the veneer as it emerges from the dryer. Since it haspassed through the dryer, all the shrinkage has occurred and theclipping of such dried hardwood veneers is to exact size. in bothsoftwood and hardwood veneer production methods there is an intermediatehandling step between the peeling of the log and the drying of theveneer.

Thus it is the object of my invention to peel veneers from the logs andconvey them without human handlingor stacking until they have passedthrough a series of conveyors and emerge from the system as dry, clippedveneer.

Another object is to produce softwood veneers which are clipped andgraded after passing through a dryer without the loss of veneer due tooversized clipping allowing for an indeterminate indefinite amount ofshrinkage.

Another object is to provide a veneer production process wherein theveneer which has passed through the dryer is accurately sensed formoisture content such that veneer which requires additional drying isaccurately detected and can be separated from veneer which has hadsufficient drying.

Another object is to provide a veneer production apparatus whichincludes a means for peeling a-log and storing the peeled veneer insufficient'amounts to feed a dryer for crosswise drying in a continuousmanner wherein there is a minimum of gap through the dryer betweenportions of the peeled veneer.

Anotherobject is to provide a veneer process which saves valuable gradesof softwood veneer from overdrying by delaying the grading process untilafter a drying step.

Other objects and advantages of this invention will be apparent uponconsideration of the following detailed description of a preferredembodiment thereof in conjunction with the annexed drawings. Variouschanges may be made, however, in the construction and arrangement ofparts in the ap paratus and certain features may be used without the useof other features. All such modifications are intended to be includedwithin the scope of the appended claims.

In the drawings:

FIGS. 1A to 1C are side elevation views of the general arrangement of aninline veneer production apparatus;

FIG. 2 is a slightly enlarged view of the center portion of the inlineveneer apparatus.

Referring now to FIG. 1 and following it from right to left and from topto bottom, the inline veneer production apparatus 1 is shown whichcomprises a peeling station 3, ribbon storage trays 2t), waste clippersection 30, dryer storage trays 40, dryer feeder 50, dryer 6t), andgrading-clipping section 79. In detail, the peeling station 3 providesthe means for bringing logs 4 by feed conveyor 5 and log handlingequipment 7 to the lathe d. Logs 4 are positioned vertically in linewith axis of the chucks 9 by charger calipers 10 or other suitablePositioning means. Logs 4 are then grasped by charger arms (not shown)which carry the log 4 forward to align the log axis with the chuck axis.Lathe 8 supports the logs '4 by means of chucks 9 which grasp the endsof the log when it is centered in the lathe 8. Once placed in the lathe8 logs 4 are rotated at a varying speed so that as the peeling knife 11is placed against the surface of the log 4, the cut material which willbe taken off by the peeling knife 11 in the form of veneer, oftenreferred to as the ribbon, can leave the lathe area at a constant speed.In this way, as the log 4 is reduced in diameter as it rotates pastpeeling knife 1 1, the speed of its rotation is increased to maintainthe same veneer speed.

During the first phase of cutting when the log surface'is notsymmetrical to the center of the lathe chucks, the cuts which are takenby the peeling knife 11 are not continuous and are generally too roughand broken to be used as veneer. Such rough-cut waste 13 is conveyed bymeans of conveyor gate 14 to a waste chute 15 where it is furtherconveyed by means of chipper conveyor 16 to be made into wood chips.Once the log 4 is cut into its smallest practical diameter for veneer,the rotation is stopped and the remaining portion of the log, referredto as the core, is released from the grasp of the lathe chucks 9 anddrops into a core discharge conveyor (not shown) to be furtherprocessed.

The desired product of the peeling process is the veneer 18 which isconveyed over conveyor gate 14 to tipples 19 which direct the ribbon ofveneer 18 into the ribbon storage trays 20. The ribbon storage traysconsist of an upper and lower section 21, 22 of four conveyor belts foreach section, which can convey the ribbon of veneer 18 from the peelingstation 3 such that as the first level of the upper section 21 becomesfull from end to end, the tipples 19 drop down to a lower level untilthat level of the conveyor belts also becomes f ull from end to end andthis process continues from the upper section 21 to the lower section22. The conveyor belts at each of these levels travel until that lengthof conveyor is completely filled from end to end with a ribbon of veneeror until the storage tray level is emptied into the next station in theinline veneer apparatus. The storage trays 20 provide a means forcarrying the ribbon of veneer 18 as it is cut from the logs d and tohave it in an abundant supply ready for the next step in the processingof the veneer, yet not requiring any handling equipment, such asforklift trucks or bins or other means for carrying the ribbon from onepart of a veneering plant to another.

As required the veneer 18 is discharged from the ribbon storage trays 20by means of ribbon storage discharge conveyor 24 which passes the veneer18 from the ribbon storage trays 20 to the waste clipper section 31).Waste clipper operators inspect the ribbon 18 as it is conveyed from thestorage trays 2t) and'use the clippers, the upper clipper 31 and thelower clipper 32, depending on the path of the veneer, to cut away largeunusable sections of the peeled veneer which are not worth passingthrough the drying process. The usable veneer is conveyed from theclippers 31, 32 by an overhead vacuum conveyor. The clipped unusableveneer 3 5 is separated from the vacuum conveyor by a scraping or othersuitable means dropping it to the waste conveyor 35 which carries it toa chipper feed conveyor 16. With the arrangement as shown, it ispossible to be discharging from the ribbon storage trays 20 from theupper section 21 through ribbon storage discharge conveyor 24 to theupper waste clipper 31 at the same time as discharging from the ribbonstorage trays lower section 22 through ribbon storage discharge conveyor24 to the lower waste clipper 32. For the most part it is anticipatedthat the waste clippers will not be cutting the veneer while it is inthe ribbon form and it will merely pass from the ribbon storage trays 20onto the dryer storage trays 40 and will only need to be clipped to cutaway the obviously unusable portions of the peeled material so that theywill not be introduced into the dryer and take up valuable dryer space.

The dryer storage trays 40 are similar in construction to the ribbonstorage trays Zll and comprise an upper section 41 and a lower section42, each section consisting of four levels of conveyor belts, which arefed by means of the waste clipper upper discharge conveyor 38 and thewaste clipper lower discharge conveyor 39 from the waste clipper section30. This second set of storage trays is provided so that an abundantsource of peeled material can be stored prior to conveying it to thedryer system. By having this abundant supply of ribbon veneer 18 thereis no need for handling equipment such as forklift trucks, carts orother means of carrying the ribbon from the waste clipper section 3i tothe dryer section 60.

From the dryer storage trays 40 the ribbon veneer 18 is feed by means ofdryer storage upper discharge conveyor 45 and dryer storage lowerdischarge conveyor 46 to dryer feed conveyor 50, best seen in FIG. 2.The upper dryer feeder conveyor 51 receives the ribbon from the dryerstorage upper discharge conveyor 45 and conveys it to the upper dryerconveyor run 66. The lower dryer feeder conveyor 52 receives the ribbonof veneer 18 from the dryer storage lower discharge conveyor 46 andconveys it to the lower dryer conveyor run 68.

Since it is anticipated that some material which passes through thedryer 60 will not be sufficiently dry in one pass to be used as plywoodveneer and must be recycled through the dryer 66 to reach the desiredmoisture content, there is provided a means for reintroducing suchsemidry veneer into the dryer 60. For convenience there is provided alower redry feeder 37 which introduces the semidry veneer to the wasteclipper lower discharge conveyor 39 so that it will pass through thelower section of the dryer storage trays 42. The semidry veneer willthen pass through the lower dryer feed conveyor 52 onto the dryer 60. Asecond redry feeder, the upper redry feeder 54, is located at the upperdryer feed conveyor i and provides a means for introducing anotherquantity of semidry veneer to the dryer.

The dryer feeder 50 is operated so that there is a constant unbrokenline of veneer material supplied to the dryer 60 so that none of thedryer volume is wasted by gaps in the material which is to pass throughit. This is accomplished by feeding the dryer 60 from the dryer storagetrays 40 in such a way that even if there are gaps in the storage trays,the storage tray conveyors can be accelerated in speed in relation tothe speed of the dryer and thus fill in any gaps that otherwise mightoccur in the dryer line. Also, since there are several layers of storagein the dryer storage trays 40 in relation to the two layers of dryerconveyor line, it is possible to keep the dryer 60 completely filled atall times. It is also noteworthy that since the veneer is introducedinto the dryer 60 with its grain crosswise to its direction of travelthrough the dryer, there are no gaps which occur in the lengthwisedrying known in the prior art wherein the wood veneers pass through thedryer with their grain lengthwise to the direction of travel.

The dryer 50 consists of a long, low, self-enclosed dryer housing 61which contains conveyors running from one end to the other which carrythe peeled veneer through the dryer heating sections 62 to the dryercooling section 63. Extending from above the dryer housing 61 are dryerexhaust stacks 65 for carrying away the excess moisture from the dryerhousing. The conveyors for the veneer consist of an upper dryer conveyor66 and a lower dryer conveyor 68. The lower dryer conveyor 68 is fedveneer 18 from the lower dryer feed conveyor 52 and the upper dryerconveyor 66 is fed veneer 18 from the upper dryer feed conveyor 51. Thedryer 60 has an air handling system for directing heated air onto thesurfaces of the veneer l8 and thus dries the veneer as it transits thedryer. At the end of the dryer 60 the cooling section 63 directs coolair onto the surfaces of the veneer 18 in order to cool the surfaces ofthe veneer for later handling.

From the cooling section 63 the veneer 18 passes to the grading-clippingsection 70 with the discharge from the upper dryer conveyor 66 beingconveyed to the upper moisture meter and marker 71 which automaticallysenses the moisture content of the veneer l8 and if it exceeds apredetermined moisture content, marks the edge of the veneer so that thegrading-clipper operator has an indication of what veneer is acceptablefor immediate use and what veneer will require a further pass throughthe dryer. in the same manner the veneer which is discharged from thelower dryer conveyor 68 is conveyed to the lower moisture meter andmarker 72. Once the moisture content has been determined agrading-clipper operator looks over the veneer to give it an overallgrade. Once this has been determined, the upper and lower gradingclippers 75 and 77 respectively are actuated to cut the ribbon of veneer18 into the exact sizes needed according to the grade given by thegrading-clipper operator. if the edge of the veneer is marked indicatingthat the moisture content is excessive, the grading-clipper operator maycut the ribbon as close as possible to the beginning of the marked areaand in this way salvage as much dry veneer as possible. Since the wettersections which must be redried may continue to shrink as they pass againthrough the dryer, the grading-clipper operator has a delay switch whichadds a percentage to the standard size to allow for shrinkage. From thegrading station 70 the veneer which has been cut to size by the upper orlower grading clippers 75, 77 is conveyed to sorting table 79 and placedin sorted stacks 80 for further processing.

OPERATION The key to efficient utilization of the inline veneerproduction apparatus herein disclosed is in the correct balance ofoperating speeds and capacities of the various subcomponents with theoptimum reached when the dryer is continuously filled with veneerribbons placed edge to edge. For this reason the storage trays arecapable of variable speeds and can be loaded at one level and unloadedat another level at the same time, to accomplish the desired result ofkeeping the dryer full.

For example, the first storage trays 20 may be loaded at one level ofconveyors of the upper section 21 at a speed of veneer travel of 800feet per minute. Tray loading may stop entirely during the loading of anew log 4 onto the lathe 3, then loading speed may increase after therough-cut waste 13 has been removed from the log. At the same timeanother level of the upper section 21 and one level conveyor of thelower section 22 of the storage trays 20 may be off-loading through thewaste clipper section 30 at up to 300 feet per minute which may slowdown as the waste clipper operator clips away unusable sections ofpeeled veneer. Thus it follows that as the veneer passes through thewaste clipper section 30 from the storage trays 20 it can feed the upperor lower sections 41, 42 of the dryer storage trays 40 at a speed ashigh as 300 feet per minute. At the same time the other conveyor levelsof the dryer storage trays 40 may be feeding veneer to the dryer feedconveyors 50 so that the dryer can be continuously operated at dryingspeed.

Thus, the time lag occurring during the loading of the lathe and theclipping away of waste material does not affect the continuous fulloperation of the dryer. With this inline mill in operation, the usualhandling of veneers after they are peeled from the lathe is completelyeliminated, therefore resulting in a considerable saving of time,personnel and money.

With this equipment it is possible to use two methods of drying. Thefirst method of drying is to pass all veneers 13, from one log whetherfrom the outer portion, i.e., the sap portion of the log, or from theinner portion, i.e., the heart portion of the log; through whicheverline of the dryer-is convenient. That portion of the veneer which is notcompletely dry as it passes through the moisture meters 71, 72 isindicated before final clipping. The grading-clipper operator may thenclip with respect to moisture content as well as grade. Those sheets ofveneer which have not been adequately dried can be recirculated by meansof the lowerredry feeder 37'and the upper redry feeder 54 or throughanother dryer;

The second alternate method of operation would pass all of the veneersfrom the sap portion of one log toone-half of the dryer storage trays40, thence into one line of the dryer for drying at one rate. Thebalance of the veneer would be sent to the other half of the dryerstorage trays and to the other line of the dryer for drying at anotherrate.- ln either case the veneers are clipped after the majority of theshrinkage has taken place.

SUMMARY In summary, the process includes the following basic steps:

The logs 4 are first hauled into the peeling station 3 and peeled by alathe 8, the resulting veneers 18 are fed into upper and lower sections21 and 22 of ribbon storage trays 20, the

veneers 18 pass from the storage trays 20 to a waste clipper sectionthat eliminates unusable veneer and from there the veneers 18 arereassembled in dryerstorage trays 40. From the dryer storage trays 40the veneers 18 are fed directly into a conveyor-type dryer 60 where theyare dried and conveyed through moisture meters 711, 72 and-throughgrading clippers 75, 77 where the veneers 18 are clipped according totheir moisture content and veneer grade. The veneers are then sorted atsorting table 79 and those which are sufiiciently dry are used to makeplywood or other lumber products and those which are too set forimmediate use are recirculated through the redry conveyors 37, 54 or toanother dryer.

l claim:

1. A process of producing veneer steps:

a. peeling logs in a peeling means to produce veneer;

comprising the following b. conveying said veneer from said peelingmeans in 40 sequence to more than one level of storagetray means; c.conveying said veneer in. sequence from more than one level of saidstorage tray means in a continuous edge-toedge supply directly to onelevel of a dryer; and d. drying said veneer in said dryer. 2. A processof producing veneer comprising the following steps:

a. peeling logs in a peeling means to produce veneer; b. conveying saidveneer from said peeling means to storage tray means; c. conveying saidveneer from said storage tray means in a continuous edge-to-edge supplydirectly to a dryer; and d. drying said veneer in said dryer, wherein;said dryer has at least two levels of conveyors transmitting its length,the veneer peeled from the sap portion of the logs is conveyed to oneset of said storage trays to supply one level of said dryer; and theveneer peeled from the heart portion of the logs is conveyed to a secondset of said storage trays to supply a second level of said dryer. 3. Aprocess of producing veneer comprising the following steps:

a. peeling logs in a peeling means to produce veneer; b. conveying saidveneer from said peeling means to storage tray means;

c. conveying said veneer from said storage tray means in a continuousedge-to-edge supply directly to a dryer; and

d. drying said veneer in said dryer,-wherein; said dryer has at leasttwo levels of conveyors transmitting its length, with one level of saiddryer operating at a lower speed than another level.

4. A process of producing veneer comprising the following steps: r

a. peelinglogs in apeeling means to produce veneer;

b. conveying said veneer rom said peeling means directly to storage traymeans; including 3 I I l. conveying said veneer from said peeling meansdirectly to ribbon storage trays,

2. conveying said veneer from said ribbon storage trays directly to awaste removal station,

3. removing unusable sections from said veneer, and

4. conveying the remaining veneer from said waste removal stationdirectly to dryer storage trays, c. conveying said veneer from saiddryer storage trays in a continuous edge-to-edge supply directly to adryer; and d. drying said veneer in said dryer. 5. An inline veneerproduction apparatus comprising in combination:

veneer drying means including at least one layer of dryer conveyorsrunning from one end to the other which carry peeled veneer through saiddrying means;

peeling means for peeling logs into veneer;

storage trays positioned between said drying and peeling means installedinline in the direction of travel of said veneer, including at least twolayers of storage trays for each layer of dryer conveyors with each ofsaid trays being provided with means for conveying said veneer along itslength;

dryer feeder conveyor means having one end adjacent each layer of saiddryer conveyors and including means to position the other end at eachlevel of said storage trays provided and means to convey veneer fromsaid other end to said one end for feeding the layerof dryer conveyoradjacent said one end; and

storage feeder conveyor means having one end adjacent said peeling meansfor receiving said peeled veneer and including means to position theother end at each level of said storage trays and means to convey veneerfrom said one end to said other end for feeding said storage trays withsaid peeled veneer.

6. The apparatus of claim 5 wherein; there are four storage tray levelsprovided for each layer of dryer conveyors.

7. The apparatus of claim 5 wherein:

said storage trays include two sets of storage trays installed inline inthe direction of travel of said veneer; and

clipper means positioned between 'said sets of storage trays forremoving unusable sections of said peeled veneer as it is conveyed fromone set of storage trays through said clipper means to the other set ofstorage trays.

8. The apparatus of claim 7 wherein; two layers of dryer conveyors areprovided in said dryer and eight levels of storage trays are provided ineach set of said storage trays.

.9. The apparatus of claim 5 wherein; said veneer is fed into said dryerfrom said storage trays with the grain of said veneer crosswise to itsdirection of travel.

1. A process of producing veneer comprising the following steps: a.peeling logs in a peeling means to produce veneer; b. conveying saidveneer from said peeling means in sequence to more than one level ofstorage tray means; c. conveying said veneer in sequence from more thanone level of said storage tray means in a continuous edge-to-edge supplydirectly to one level of a dryer; and d. drying said veneer in saiddryer.
 2. A process of producing veneer comprising the following steps:a. peeling logs in a peeling means to produce veneer; b. conveying saidveneer from said peeling means to storage tray means; c. conveying saidveneer from said storage tray means in a continuous edge-to-edge supplydirectly to a dryer; and d. drying said veneer in said dryer, wherein;said dryer has at least two levels of conveyors transmitting its length,the veneer peeled from the sap portion of the logs is conveyed to oneset of said storage trays to supply one level of said dryer, and theveneer peeled from the heart portion of the logs is conveyed to a secondset of said storage trays to supply a second level of said dryer. 2.conveying said veneer from said ribbon storage trays directly to a wasteremoval station,
 3. removing unusable sections from said veneer, and 3.A process of producing veneer comprising the following steps: a. peelinglogs in a peeling means to produce veneer; b. conveying said veneer fromsaid peeling means to storage tray means; c. conveying said veneer fromsaid storage tray means in a continuous edge-to-edge supply directly toa dryer; and d. drying said veneer in said dryer, wherein; said dryerhas at least two levels of conveyors transmitting its length, with onelevel of said dryer operating at a lower speed than another level.
 4. Aprocess of producing veneer comprising the following steps: a. peelinglogs in a peeling means to produce veneer; b. conveying said veneer fromsaid peeling means directly to storage tray means; including 4.conveying the remaining veneer from said waste removal station directlyto dryer storage trays, c. conveying said veneer from said dryer storagetrays in a continuous edge-to-edge supply directly to a dryer; and d.drying said veneer in said dryer.
 5. An inline veneer productionapparatus comprising in combination: veneer drying means including atleast one layer of dryer conveyors running from one end to the otherwhich carry peeled veneer through said drying means; peeling means forpeeling logs into veneer; storage trays positioned between said dryingand peeling means installed inline in the direction of travel of saidveneer, including at least two layers of storage trays for each layer ofdryer conveyors with each of said trays being provided with means forconveying said veneer along its length; dryer feeder conveyor meanshaving one end adjacent each layer of said dryer conveyors and includingmeans to position the other end at each level of said storage traysprovided and means to convey veneer from said other end to said one endfor feeding the layer of dryer conveyor adjacent said one end; andstorage feeder conveyor means having one end adjacent said peeling meansfor receiving said peeled veneer and including means to position theother end at each level of said storage trays and means to convey veneerfrom said one end to said other end for feeding said storage trays withsaid peeled veneer.
 6. The apparatus of claim 5 wherein; there are fourstorage tray levels provided for each layer of dryer conveyors.
 7. Theapparatus of claim 5 wherein: said Storage trays include two sets ofstorage trays installed inline in the direction of travel of saidveneer; and clipper means positioned between said sets of storage traysfor removing unusable sections of said peeled veneer as it is conveyedfrom one set of storage trays through said clipper means to the otherset of storage trays.
 8. The apparatus of claim 7 wherein; two layers ofdryer conveyors are provided in said dryer and eight levels of storagetrays are provided in each set of said storage trays.
 9. The apparatusof claim 5 wherein; said veneer is fed into said dryer from said storagetrays with the grain of said veneer crosswise to its direction oftravel.